If you’re heading to a Christmas tree farm, heed the research of tree scientist Les Werner and his students:
Keep that fresh-cut fir or pine watered once you get it home, and you’ll be rewarded with fewer needles to sweep off the floor.
Werner for years thought that keeping water in the Christmas tree stand was pointless.
The University of Wisconsin-Stevens Point associate professor of forestry never watered his own family’s Christmas trees because he reasoned trees stop photosynthesizing when they’re cut from their root systems.
“For years, I asked plant physiologists around the country, ‘Do you water your Christmas tree?’ ” Werner says. “Most of them, like me, said they didn’t. But their wives would water the tree behind their back.”
So Werner and two students decided to document moisture loss in cut Christmas trees that were watered versus those that weren’t. A tree farm donated 54 fresh-cut trees for a four-week study.
Werner’s team set out to study whether loss of a root system, combined with an unnatural indoor environment, would severely limit a cut Christmas tree’s biological functions, including water uptake, photosynthesis and transpiration.
The research proved a direct correlation between needle retention and moisture content, Werner says. Needle moisture in unwatered trees diminishes significantly over time, while watered trees maintain needle moisture.
Based on the research, he advises consumers to buy as fresh a tree as they can – or to cut their own tree – if they don’t enjoy sweeping needles.
“Then make sure you give it plenty of water for at least the first week and a half, when it takes up the most water,” Werner says.
After about a week, the tree will respond to the cut on its trunk by excreting resin, which naturally seals the “wound.” Then it no longer takes up as much water.
Cutting a few inches off the trunk before putting it in the stand opens the capillaries to allow the tree to draw moisture up the trunk and into the needles, Werner says. The water level should be two to three inches above the cut.
For those who believe in adding sugar, aspirin or vodka to the tree water, none of those so-called additives will help, Werner says.
“I would love to come up with an additive that works,” he says. “Clean water still works the best.”